The atmosphere of one of the most extreme exoplanets known to us is composed of titanium oxide, iron, titanium, chromium, vanadium, magnesium and manganese, among other things. In addition, analysis of the celestial body called WASP-189b revealed a three-dimensional structure for the first time and found evidence of thermal effects such as winds.
A research team led by Bibiana Prinoth from the University of Lund in Sweden was able to do this using high-resolution spectroscopy. The tools used to study such extreme gas giants in such detail would soon make it possible to study smaller and more Earth-like exoplanets as well. So that’s another step in the search for extraterrestrial life, says Prinoth.
Gaze into a world 300 light years away
WASP-189b was discovered in 2018 and is 322 light-years from Earth. The exoplanet is 1.6 times the diameter of Jupiter and is so close to its star that it takes just 2.7 Earth days to complete one orbit. With sometimes 3200 degrees Celsius, it surpasses many a red dwarf star. Observations with ESA’s CHaracterising ExOPlanet Satellite (CHEOPS) have also shown that it rotates so rapidly that its radius at the equator is significantly larger than at the poles, while the deformation is not as extreme as that of WASP-103b, the more like a rugby ball. WASP-189b also does not orbit its star in its equatorial plane, as would be expected if it formed from the protoplanetary disk. Rather, its orbit is at right angles to it across the poles of the star.
Prinoth explains that the view into the atmosphere of WASP-189b has now succeeded with high-resolution spectrographic images. They were taken when the exoplanet was in front of its star from our perspective. By subtracting out the spectrum of the starlight, those parts of the light that interacted with the gas giant could be analyzed. This enabled the researchers to identify the metals that are present there as gases. Above all, the first detection of titanium oxide in such an environment is significant, they explain. But the finding of differences in the distribution of the gases is also a novelty and shows how far the technology has come. The study was published in the US journal Nature Astronomy.
(mho)